Safety-guard for presses



H. OSSWALD.

SAFETY GUARD FOR PRESSES.

APPLICATION FILEDAPR. 15. 191s.

Patented Oct. 4, 1921.

2 SHEETS-SHEET 1.

H. 0sswAL`D. SAFETY GUARD FOR PRESSES.

APPLICATION FILED APR.15,1918.

1,392,699. l Patented 0@t.4,1921.

2 SHEETS-SHEET 2.

A TTOH/VEY .one revolution and HERMAN OSSWALD, 0F RICHMOND HILL, NEW

YORK, ASSIGTN'OR TO THE V. & 0. PRESS COMPANY, A CORPORATION OF NEW YORK.

SAFETY-GUARD FOR PRESSES.

Application led April 15, 1918.

To all whom t may concern.'

.Be it known that I, HERMAN OsswALD, a citizen of the United States, residing at Richmond Hill, in the county of Queens, State of New York, have invented certain new and useful Improvements in Safety- Guards for Presses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

his invention relates to safety devices for presses and is directed particularly to the provision of an improved form of guard to be applied to punch presses and like machines to protect the operator against injury.

The invention is punch presses of the type wherein a treadle is depressed to actuate a clutch whereby the operating shaft of the machine is connected to the power wheel to cause it to make then come to rest if the treadle be released at'once or to continue in operation so long as the treadle is held depressed. One feature of the invention involves the provision of means for guarding against the possibility of injury to the operator in case the treadle is depressed to operate the clutch and immediately released. In many forms-of press gua-rds as heretofore constructed, provision has been made for lowering a guard over the lower die as the pedal of the machine is depressed, but in these machines the release of the pedal immediately after itisrdepressed to operate the clutch results in the return of the Vpedal by its retracting spring and elevation of the guard. Such a construction admits of the possibility of injury to the operator as a result of reaching inunder the guard after the latter has been raised with the raising of the pedal and before the voperating shaft has rotated 'sufficient to carry the upper die downward into'engagement with the lower die. One of the objectsy of the present invention is to improve upon the construction of press guards of this type as heretofore constructed by insuring that when the guard is lowered as an incident to depression of the pedal, it will remain in its lowered position, preventing the operator from insering his hand under the upper die, until the operating shaft has rotated far enough to completely eliminate thepossibility that the Specification of Letters Patent.

of special utlility inl Pttned 001]. 4, 1921. serial No. 228,565. l

operator may get his hand between the dies while the upper one is moving downward.

The invention also involves the provision of an improved form of press guard which is simple in construction, which may be manufactured and installed at low cost, which 1s reliable in operation, and which is adapted for ready adjustment in accordance with changes of the position of the rocking frame of the press upon the pedestal.

he features of the invention will be better understood by reference to the following description taken in connection with the accompanying drawings, in which Figure 1 is an elevation of a punch press provided with my improved protective device; Fig. 2 is a front view of the press; Fig. 3 is a horizontal section on line 3-3 of Fig. 1; Fig. 4 is a sectional detail view on line 4 4 of Fig. 1; Fig. 5 is a perspective view of the controlling member; Fig.- view of theclutch dog; Fig. 7 is a vertical sectional detail view through the clutch dog; Figs. 8 and 9 are sectional detail views corresponding to Fig. 7 and illustrating different positions of the parts; and Fig. 10 is a view of a portion of the operating shaft 6 1s a perspectiveV showing the controlling member in section.

'be turnedabout the axis 13. The construction of the press as a whole in these and other respects may be and preferably is that illustrated and described in Patent No. 769,955, granted to me September 13, 1904.

The operating shaft 17 is mounted in bearings on the rocking frame which overhang the bolster 1S upon which the die 18 is mounted, the lconstruction being such that the slide 10 may be extended up in rear of the operating shaft 17 to provide an elongated bearing surface in the guidewa vided for the slide in the frame 12. n the shaft 17 is an eccentric 47 for reciprocating prothe slide and the upper die in the usual manner. The power wheel 19 is mounted loosely upon one end of the operating shaft 17. In the face of one of the hubs ofthe D Jframe of a size adapted to inclose the die power wheel are recesses 20. Adjacent to this hub of the wheel 19 the power shaft 17 is provided with an enlargement 21 and in this enlargement is a guideway extending parallel to the axis of the shaft for the reception of a dog 22. The dog is shown in perspective in Fig. 6. Within it is a recess for a spring 23, one end of which engages the bottom of the recess and the other end of which engages a stud or projection 24 on theenlargement 21 so that the spring exerts a pressure on the dog continuously tending to move it to project its end into one of the notches or recesses in the hub of the power wheel 19. y

ln the enlargement 21 of the operating shaft is a circumferential groove and the dog 22 isprovided with a recess which alines with this groove when the dog is in its retracted position. The groove in the enlargement 21 and the recess in the dog 22- are adapted for coaction with a controlling member 25, shown in perspective in Fig. 5. This controlling member is mounted for. movement in the direction of its length in a .guideway formed on a plate 26 which is secured to one of the side frames of the press. Suitable provision is preferably made for permitting the mounting of the plate 26 upon the frame of the press in any position within a prescribed angular range about the axis of the operating shaft 17. The controlling member 25 has a stem 27 secured to it and passing through an opening in a guide formed onthe plate 26. A spring 28 is coiled upon thestem 27 and is under compression between the controlling member 25 andthe guide for the stem. The spring therefore tends constantly to press the controlling memberl 25 forward into the groove inthe hub 21. The end of the stem 27 is pivotally connected to a lever 29 which is pivotally mounted upon the plate 26.

The controlling member is operated to withdraw it from the groove in the hub by means of a pedal 30 pivoted upon the pedestal of the machine and held yieldingly in a raised position by a coiled spring 31. A rod 32 isfpivotally connected at its lower end to the pedal 30 and at its upper end to the supporting frame of the press guard.

`Referring to Fig. 3, it will be seen that a rock shaft 33 extends between the side frames of the press and is adapted to rock in bearings formed therein. On one end of the shaft 33 is a crank 34 to which the upper end of rod 32 is secured by a screw 35 which permits of securing rod 32 to crank 34 at any position along the length of the rod required by the angular position of the rocking frame 12 on the pedestal 11. On

the rock shaft 33 is secured a support 36 carrying the press guard 37 which may be of any desired construction. In the present instance it is shown as a rectangular 19 when the guard is depressed, and this frame may have a wire lattice or any similar form of protective device mounted thereon. A second rod 38 is secured 'to the crank 34 by a screw 39 similar to the screw 35, and extends upwardly therefrom to the pivoted lever 29 to which it is pivotally connected. 1

Referring more particularly to Figs. 5 to 10 inclusive, it will be noted that one wall 40 of the recess in the dog 22 is curved'or inclined and that the forward lend of the controlling member 25 is correspondingly curved or inclined at 41. Also, the end 4 2 of the controlling member 25 is curved to correspond with the curvature of the 'bottom of the groove inthe hub 21. The bottom of the groove in the hub 21 is provided with a recess at the point in the' groove with which the end of the controlling member coacts when the operating shaft is at rest. This recess is shown at 43 in Fig. 10. The forward end of the recess is tapered, as indicated at44, by the provision of an inclined wall atthe forward end of the recess corresponding to the inclined wall 41 on the controlling member25 Referring. to Figs. 7, 8 and .9, particular attention is directed to the depth of the circumferential groove in the hub 21 at diderent points about the circumference. The depression or recess in the bottom of the groove is shown at 43. Beyond'this depression in a direction opposite to the direction ofV rotation of the shaft with its hub, the groove is quite 105 shallow, as indicated at 45. This portion of the groove which is relatively shallow extends approximately half-way around the axis of the shaft. The groove then becomes deeper so that its normal depth is reached at 110 about the point indicated by the refer-f ence 46. Y

The operation of the mechanism constructed in this manner will now be described. The operator depresses the pedal 30, thereby 115 drawing the rods 32 and 38 `down and rocking the shaft 33 carrying the guard 37 so as to move the guard from the full line position shown inV Fig. 1 to the dotted line position, inv which position it effeetually precludes injury to the operator by inserting his hand between the two dies. Also, the downward movement of the pedaland the rods 32 and 38 causes the lever 29 to be rocked on its pivot, thereby drawing the lV and from the recess in the dog 22. The dog is then moved in the direction of its length by its spring 23 and its end is projected into one of the recesses in the hub of the power wheel 19. This connects the power wheel to the shaft 17 and the latter is rotated and acts through the' eccentric 47 to reciprocate the slide 10 and the upper die carried thereby. The retractile movement of the controlling member 25 carries it beyond the bottom of the shallow portion 45 of the groove in the hub 21. The shaft 17 begins to rotate with the power wheel 19 and if the pedal 30 be inmediately released, the springs 31 and 28 exert a tension tending to raise pedal 30 and rods 32 and 38 and move the controlling` member 25 toward the axis of the shaft 17. This movement carriesr the end of the controlling member into contact with the bottom of the groove in the hub at the portion 45 of the groove where it is quite shallow. The outward movement of the controlling member carries it but little beyond the level of the bottom of the shallow portion of the groove so that this inward movement would be very small, so small that the accompanying upward movement of the pedal 30 and guard 37 would be so slight as to be negligible. The operating shaft continues its rotation with the end of the controlling member -riding upon the bottom of the groove in the hub 21 and when the deeper portion 46 ofthe groove comes under the controlling member, the latter moves inwardly toward the axisof the shaft and the pedal 3G and guard 37 are raised correspondingly. When the depression 43 comes under the controlling member 25, the beveled end of the controlling member enters the recess in the dog 22 and -engages the inclined wall of the recess and the cam action of these two coacting parts operates to move the dog 22 against the tension of its spring 23 so Aas to withdraw its end from the recess in the hub of the power wheel. This disconnects the operating shaft 17 from the powerrwheel. Also, the end of the controlling member enters the depression 43 and moves along therein until the inclined wall 41 of the end of the controlling member comes into engagementwith'the inclined wall of the tapered end 44 of the recess 43 in the bottom of the vgroove in the hub, and the engagement of these two walls brings the operating shatt 17 to rest. This precludes the possibility of continued rotation of the operating shaft when such continued rotation is not intended, such as is commonly termed repeating. Of course, continued operation of the shaft 17 without interruption may be secured if desired by merely holding the pedal 30 in the depressed position, in which case the controlling member 25 would be held in its outermost position in which it is shown in Fig.,8, thus allowing the power shaft 19 to drive the operating shaft 17 as long as continuous operation of the machine is desired. But on release of the pedal 30, the controlling member 25 moves into engagement with the bottom of the groove in the hub 21 and insures a discontinuance of the rotation of the operating shaft by its engagement with the wall at the end of the groove 43. 1n every case, however, it will be noted that the controlling member 25 is held positively in an outer position by the bottom of the shallow portion 45 of the groove in the hub 21 until the operating shaft has made substantially a half revolution and its retention in this outer position insures that the guard 37 will be held in position until the upper die has been lowered into engagement with the lower die. 1t will be. noted also that the connection of the rods 32 and 38 to the cranlr 34 by releasable devices permits of shifting the angular position of the rocking frame 12 on the pedestal 11 and then readily establishing vthe desired connection from the pedal 30 to the guard and the controlling member so that those parts will be operated by the pedal in the manner above described.

1 claim:

1. A punch press having an operating shaft, a power member, a dog movable on the operating shaft in the direction of the axis of the shaft into engagement with the power member to connect the power member to the shaft, a controlling member for positioning the dog, means for moving the controlling member outwardly from the shaft to releasel the dog, a guard connected to the controlling member so as to be moved to its operative position when the controlling member is moved to its outer position for releasing the dog, and means for holding the controlling member in substantially the position to which it is moved to release the dog during substantially a half revolution of the operating shaft; substantially as described.

2. Arpunch press having an operating shaft, a power member, a dog mounted for movement in the direction of its length upon the operating shaft to carry its end into engagement with the power member, a controlling member whose end is adapted to enter a circumferential groove on the operating shaft to coact with the dog, a guard, and an operating device connected to the guard and to the controlling member for moving the guard to its operative position and for moving the controlling member to cause it to release the dog, the said groove being of relatively shallow depth over substantially half of its lengtn to hold the controlling member in substantially the position to' which it is moved to release the dog during substantially one-half of a revolution its depressed or operative of the operating shaft to maintain the guard in its operative position while the die reciprocated by the operating shaft is moved intov engagement with the work; substantiallY as described.

3. i punch press having a power member', an operating shaft, a dog movable in the direction of its length upon the operating shaft to carry its end into engagement with the power member, a controlling member, a groove on the operating shaft in which the controlling member is adapted to move to coactwith the dog, a guard, and an operating device connected to the guard and the controlling member, the groove in the op- Y erating shaft having a depression therein with which the controlling member coacts to arrest rotation of the shaft and having the portions thereof on opposite sides of the depression of different depths whereby v when the switch is in the portion of the groove of less depth, the guard is held in its operative position; substantially as described;

4t. A punch press comprising a 'power member, a die, a guard for the die, an operating shaft for the die, a clutch dog provided Vwith a transverse groove movable longitudinally of the operating shaft for operatively connecting the shaft and power l member, the operating sh ft being provided with a circumferential groove, a transversely movable controlling member adapted to coact with the groove in the dog and with the circumferential groove in the operating shaft, and means for operating the guard and the controlling member whereby the dog moves to clutching position when the guard is moved to operative position and is moved to the unclutching position by the controlling member after more than half a 'revolution of the shaft has been completed.

5. A punch press comprising a power member, an operating Shaft provided with a circumferential groove varying in depth, a dog provided with a transverse 'groove adapted to register with said circumferen tial groove, said dog being longitudinally movable of the operating shaft for clutching the operating shaft to the power member, a transversely movable controlling member curved to ride in said circumferential position, a guard for a die, and operating means connected to said guard and to 'the said controlling member.

6. A punch press comprising a powel'. member, an operating shaft provided with a circumferential groove varying in depth, a dog provided with a transverse groove one wall of which is beveled, movable longitudinally of the operating shaft for clutching the operating shaft to the power member, a controlling member movable trans versely of the operating shaft'provided with a beveled edge adaptedto engage with the beveled wall of the groove in the dog and move it to the'unclutched position, a guard for a die, and operating means connected to the guard and the controlling member.

7. The combination in a punch press of a power member, an operating shaft, a dog movable along the operating shaft into and out of engagement with the power member, said shaft and said dog each being provided with a groove one wall of which is beveled7 a transversely movable controlling member provided with a beveled end adapted to cooperate with the grooves in the dog and the shaft for moving the dog to the unclutched position, and for stopping the'rota'tion of the shaft after the dog has been unclutched.

8. The'combination, in a punch press, of a guard, a power member, an operating shaft, a. clutch dog movable longitudinally along thefshaft and rotatable therewith, for clutching the power member and the operating shaft together, a controlling member movable transversely of the operating shaft into and out of engagement with the dog, a spring for moving the controlling member inwardly into engagement with the dog so that the rotation of the shaft dog causes the controlling member to move the dog longitudinally Vofthe shaft to the unclutched position, and foot-operated 'means Y for moving the controlling member out of engagement with the dog, and means for preventing said inward movement of the controlling member until substantially half a revolution of the shaft has been completed.

In testimony whereof I aix my signature.

HERMAN osswALn. 

